Piston packing



Sept. 13, 11932; L. C. MARSHALL 1,877,414

PISTON PACKING ,original Filed Feb. 13, 1925 20 24 I 71u@ ratOr-np Patented Sept. 13, 1932 UNITED STATES 'PATENT-OFFICE j LEWIS C. ILABSHALL, 0F. 'WALPQLIL IASACHUSETTS, ASSIGNOR, BY ASSIGN- MENTS, "I0 THE SIMPLEX PISTON RING COMPANY OF mEIcL'lNc., OF

LAND, OHIO, A CORPORATION OE .OHIO

l rrsromJ PACKING Application led February 13, 1925, Serial No. 8,933. Renewed January 18, 1888.

This invention pertains to m'etallic piston Figs. 8;, 9, 10 and 11 are fragmentardepackings and more particularly to split ring veloped views v also .showing rings ren ered packings of the type employed. in internal resilient by the provision of inclined slits and combustion engines. illustratin various modifications of the split Principal objects of the invention are to or lgap an of the end portions of the ring; provide a packing ring furnished withoil an Y scraping and recelving means; to provide an i improved packing of simple and sturdy conveloped views showing axially resilient rings struction a plicable to one piece pistons havhaving slits 1n planes perpendicular to the ing circumferential packing grooves of fixed axis'of the ring, illustrating various modes Width and inherently capable of close contact of makin the rings resilient in the neighbor# with' the opposite side walls of the piston hood of t e gap. groove; to provide a unitary split ring slitted Referring to' the drawing thenumeral 1 to make it axially resilient, or compressible designates a packing ring which may be used and which can be manufactured rapidly and alonev inthe piston groove, or, as here illuswithout excessive labor; to

piece axially resilient split rm'g free from pander ring 2 of any usual construction. -thin and fragile ton es-or projections at its The ring 1 is providedv at one point with Figs.. 12, 13, and 14 are fragmentary -derovide a one trated, be 'associated with an-internal exl ends; and to provi ea split ring which is theusual transverse gap, indicated at 3,

axially resilient at substantially all points which permits the ring to ex and radiall of its circumference including the regions of 'In the preferred form of pacllng herein i the split or gap. lustrated the main ring 1A is rendered axially In the accompanying drawing one precompressible or resilient by providing it with ferred embodiment of the invention is disa plurality of over-lappin slits 4 which exclosed by way 0f example together with certend through the entire radial thickness ofl 75 tain modified features of'construction which the ringA and which arefdisposed in planes may or may notQbe combined with one lan- `inclined to the plane of the rin Preferably, other as --experience or circumstances may the angle between the plane o a slit and the warrant. f i plane of the ring is not over 45, although a Fig. 1 is a perspective view of a split ring greater angle may'sometimes prove desirable, packing embodying the present invention, but whatever the angle of the slits, the latter showing such packing as comprising-amain are closed at both ends'z leaving the upper expander rings;

axial resiliency;

outer ring having series of inclined slits and lower edges of the rlng smooth and contherthrough, and aminner follower or extinuous except at the gap 3. pander ring, the forward portion of the lat- Referring to Fig. 2 a portion ofthe side ter being broken away,- wall of an engine. piston is vindicated in sec- Fig. 2 is aA fragmentar` radial section' -tion at 5, such wall being provided with 'the through a piston showing t e ring of Fig.l "1 usual circumferential groove y8 `in its outer seated in the piston groove; 1' surface for the receptibnqf the packing ring. Figs.' 3, 4 and 5 are views similar to Fig. This groove is formed with spaced side walls 2 but illustrating modified forms fmain and 6 and 7 respectively which are perpendicular to the axis of the ring. The ring 1 is normally somewhat wider 1n an axial dirpction Fig. 6 is a fragmentary devel ped view 4; of the ring of Fig. 1 showing'one arrange-v than the groove in the piston and im order p vment of the` split or gap designed to make oto seat the ring in the groovefit is necessary .the ring resilient at opposite sides 'of the to compress the. ring axiall gap; pressed the ring may A Fig'. 7 is a view similar o Fig. 6 showing groove and then bylts inherent resiliency a modified arrangement providing greater it presses in oppo'slte directions against the l" 1 walls 6 and 7 of the groove so that recipl'otza4 0' tion f thering in the' groove is entirely prevented. The ring thus devised, effectuallly prevents oil pumping, with its attendant cylinder wall and for a greater length of time, than does the ordinary ring.

As shown in Fig. 2 the maln ring 1 is .furnished with aL groove upon its inner peripheral surface, such groove having bevelled upper and lower faces, and the expander ring 16: 2, arranged behind the main ring,

' circumferential slot 3.

vprovides over-lapping tongues 9 and 10 at v the ends of the ring, and in the arrangement has a curved outer surface which bears against the inclined faces of the groove ofthe main ring 1. l In Fig. 3 I have illustrated .a main ring 1 which maybe of the typeillustrated in Fig. 1 or of any of the other types hereafter described. In this arrangement no expander ring is employed and the inherent tendency of the split ring 1 to expand-radially is depended upon to 'hold it in contact with the cylinder walls. Y

In Fig. 4 I have illustrated a further modified form of main ring designated 1a. This ring is grovided at its inner face with a groove simi ar to that of the ring 1 shown in Fig. 2 but the expander ring 2"L is furnished' with bevelled faces engageable respectively with the bevelled surfaces of the groove.

In Fig. 5 the main ring 1"` is of further modified construction havin a groove of arcuate contour at its inner,v le, and the expander ring 2b is formed off-round or other suitably shaped wire in the usual manner,

such ring engaging the concave surface ofv the groove of the main ring.

Referring to Fig. fiiwhichshows asfragmentary developed portion of the main ring of Fig. 1 the end most slits of the series of slits 4 are indicated by the numerals 4'l and 4b respectively. he gap in respectively united at their inner ends by a This arrangement here illustrated the endmost slits 4 and 4" extend 'into' these tongues and almost tothe extremities of the latter. However, the slits dd notl extend entirely tothe ends of the tdngues so that the ends of the slits are'closed by solid metal. This arrangement provides for over-lap of the slits 4* and 4b when the ring is closed so that the' axial resiliency or compressibility of the ring is maintained even at the region ofthe gap but without leaving the ends of any of the slits open.

If the ends of the slits were left open at opposite sides of the'gap the resulting long thin tongues of metal supported only at one the-ring ywhichv permits it to expand radially comprises two circumferentially offset axiallyextending slots-3I| and 3P" end would be so fragile and easily broken is avoided and the meeting faces of the ring are imperforate and strong while at the same time the ring is axially compressible at the region of the gap.

In the arrangement shown in Figs. 1 and 6 the slits 4 over-lap somewhat less than one half of their respective lengths but in the ring shown in Fig. 7 the slits 24 overlap a distance greater than one-half their respective lengths' so that at any section, for example thatindicated by the line w-b, at least three slits will be found in over-lapping relation. A ring thus formed is even more compressible and resilient in an axial direction than thejring 'of Fig. 1, and it is clear, that if'the ring be of suiiicient width to permit it, Ivan even greater overlap of the slits, with corresponding increase in axial resiliency may be obtained.

In the arrangement shown in'Fig. .7 the ring 2() is provided with a gap ,conveniently formed by extending slots 23? and 23b inward from opposite edges of the ring to shown in Figi the endmost slits of the series extend well down into the overlapping end portions of the ring soas to maintain the resiliency of the ring throughout.

In the arrangement shown in Fig. 8 the ringf 30 is provided with inclined slits 34 to make it axially resilient and at offset points 'slots 33l and 33b are extended inwardly from opposite edges ofthe ring to intersect one of the slits, for example the slit 33,. of the series ofinclined slits.

latter. This arrangement may be found desirable under certain circumstances although that shown in Figs. 6 and 7 is regarded as preferable.

Referring to Fig. 9 the ring 40 is shown as provided with inclined slits 44 and the ios In this case the slots 33` and 33b intersect the slit 33 at points intermediate the ends of the gap in this ring is formed by a single i..-

clined slot 43 which intersects one vof the slits 44, for example the slit 44, substantially atits central portion. In .this arrangement the meeting ends of the 'ring are not solid but nevertheless the formation lof thin and narrow. tongues of metal is substantially avoided.

In Fig. 10 the ring50 is shown as provided with inclined slits 54 to make it axially resilient and is furnished with a slot 53 providing a gap in the ring. Thisslot 53 extends diagonally through thering and is inclined oppositely to thevslits 54. The slot -53 forms overlappingend portions 59 and these endportions are made axially resilient by the provision of slits and 56 which in this case are parallel to the plane of the ring )and which overlap each other and also the "ends of the adjacent slits 54.

The arrangement shown in Fig. 11 resembles thatshown in Fig. 1 in manv respects as the ring Ais provided with aseries of inclined slits64 and with a gap. fito make the ring radially resilient, but in this case the slits 64 do not overlap to any substantial extent so that the ringis not compressible in an axial direction to any appreciable degree. While the ring thus devised isnot as desirable from many standpoints as the other forms of ring illustrated it may be used in the manner of an ordinary packing ring but with the advantage of having oilscraping means extending throughout its lentire circumference. While no continuous groove of the type commonly employed for oil scraping is provided, the ultimate eiect of the seriesof slits 64, so far as oil scraping is I8 concerned is substantially the same as that of a single continuous groove.

In Fig. 12 the ring 7 0 is shown as provided with overlapping slits 74 arranged in planes parallel to that of the ring. The ring is fur- 60 nishedwith a diagonal ga 73 which delines overlapping end portions 9 of the ring and these end portions are rendered axially resilient by means of inclined slits 75 which over'- lap each other and the adjacent slits 74.

In Fig. 13 the ring 8() is made axially resilientbyl overlapping slits 84 and the gap in the ring comprises inwardlydirected slots 83 intersecting the inclined slot 83. The overlapping portions 89 ofthe ring are made ax- 'ially resilient by extending the end most slits 84 into-these overlapping portions so that the endmost slitsove'rlapeach other. If desired, these endmost slits may be special slits, shorter than the slits of the series proper, although ordinarily this is not necessary.

In Fig. 14 the ri`1g-90 is shown as provided with overlapping slits 94 arranged vin planes parallel tothe'plane of the ring and the gap in the ring comprises inwardly directed offset slots 93a' intersecting a slot 93b which is parallel to the lane of the ring. In

thisv case also the over apping end portions of the rin are axially resilient.

While have endeavored to show various desirable embodiments ofthe invention it is toh be understood that the inventiongisl not necessarilylimited in its application to the arrangements 'herein specifically shown and described but that it is undoubtedly capable of embodiment in other specific arrangements which will occur to those skilled in the art. It'is also to be understood that the invention is not limited to the particular proportions of y lparts herein illustrated or to any specific combination of main`and expanderrings or to any particular material, and that While the packing is particularly desi ed and intended for use in the pistons of internal combusj tion engines it is not necessarily limited to such use. i

I claim: l A

1. A pistonV packing comprising a main split ring provided with a plurality of slits extending through its entire radial thickness, said slits being so disposed in planes inclined to the plane of the ring as to make the ring i axially elastic, and a follower ring engaging the inner surface of the main ring and arranged to exert force on the main ring tending to expand it axially and radially.

2. A piston packing comprising a mainA split ring provided with a circumferential groove in its inner peripheral surface,` and having narrowv slits extending through its entire radial thickness, said slits being inclined to the plane of the ring and overla ping at their ends the an le of inclination o the slits to the plane of t e ring being less than 45, whereb to render the ring axially resilient,- and a ollower ring engaging the groove in the inner surface of the main ring.

3. Alsplit packing ring provided. with a plurality of narrow overlapping slits passing through its entire thickness, said slits being closed at both ends, the slits being disposed in planes inclined to the plane of the ring at such angles as to render the ring axially elastic. v 'i 4. `A piston packing comprising a split main ring provided with a plurality of narrow slits closed at both ends extendingthrough its entire radial thickness, said slits beinv' disposed in planes inclined to the plane of the ring, and a radiallyexpansible follower ring engaging the inner surface of the mainring.

5. A packing ring provided with a gap at onev point, said gap being so arranged that the Y Y ness and so disposed as to make the ring axially elastic, and other slits, similar to but lying in lplanes intersect-ing the planes of the liirst.

' end portions o f the ring overlap to break the joint, said ring havin a plurality of narrow slits extending throug its entirel radial thlck- Y 6. A packing rmg provlded with a gap at 4 one point, the ends of the ring overlapping at the 'gap to break the joint, said ring being provided with a plurality 'of slits extendling through its'entire radial thickness, some y .at least of said slits being inclined 'to thc e plane of the ring and vcertain'slits extending into the overlapping end portionsof the ring.

7. A packing -ring provided/with a gap at onepoint, the ends of the ring overlapping at the gap to b reak the joint, said ring being provided with a series of overlapping slits passing through its entire radial thickness, said shts being inclined'to the'planeo the 4' Y .l j y1,977,414 Y rin and other slits lying in planes substantia yperpendicular' to the axis of the rlng extendmg into said overlapplng end portions.

8. A split packing ring provided with slits extending through its entire thickness in a radialdirection, said slits being closed at both endsA and inclined to the plane of 'the ring, the end of one slit being disposed closely adjacent `to one edge of the ring and the. end ofthe nextslit being disposed closely adjacent to the opposite edge of the ring.

9. A split packing'ring provided with-fa series of slits eachextending through its entire thickness in a radialdirection and each closed at both ends, therslits of said series being staggered and the end of one 'slit being disposed adjacent to one edge of the ring and the end of the next slit being disposed adjacent to the'opposite edge of the ring, each slit of the series being inclined to the plane of the ring at an angle not greater than 450, the aggregate effect ofthe series of slits being similar to that of a single continuous circumferential oil scraping groove opening j from the exterior to the interior of the ring. 10. In a piston ring having parallel axial. faces, a series of inclined overlapping slots extending through the ring, the axial faces of the ring being split at pointsonboth sides of the middleof one of said inclined slotsby parallel 'cuts whichA extend from'said slots to therespective axial faces, thus forming a step junction. f

11. In a pistoni ring-having parallel axial faces, a serles of inclined overlapping slots extending through the ring, the axial faces of the rin being split at points on both sides of the mi dle of one of said inclined slots by 40 parallel cuts which extend from said slot to the respective axial faces, thus forming a step junction, both ends of said junction beb ingsymlnetrical. y

12. In a piston'ring having parallel axial l faces, a series of incl-ined overlapping'slots extending through the ring, the axial faces of the ring being split at points on both sides of the middle' of one of said inclined slots by parallel cuts which extend from said slot to I.. the respective axial faces, the portion of inclined slot between the cuts being the over# lap, and the respective overlapping faces be- 1n spaced apart from each other.

igned by me at lBoston, Massachusetts,`

this 12th .day of February, 1925.

. LEWIS c. MAEsHALL. 

